the need for ice detection standards jarkko latonen, labkotec

The Need for Ice Detection

Standards

By Mr Jarkko Latonen, Labkotec

in collaboration with VTT

Abstract and poster presentation at Winterwind 2012

Ice Detection is Needed in Wind Turbines

• To detect when ice build-up starts

• To prevent dangerous ice-throw

• To prevent energy loss

• To protect the wind turbine

How to ensure that ice detection works?

There should be

• certification rules

• standards and

• published best practices

for icing or ice detection tests

Labkotec’s Pre-Certification process for LID-3300IP Ice Detector

Labkotec wanted to

• Ensure that LID-3300IP meets

standards demanded by modern

wind energy operators and

• Express the need for standards

Neutral Third Party for Testing

• Selected partner VTT, Technical Research

Centre of Finland due to extensive know-how in

icing and ice detection

Evaluation Method Development

• In-house methods developed by VTT

• Based on ice detection time in

“standard” icing conditions

• Pre-certification process to be the

precursor to the formal Ice Detection

Standard

Test Methods

• Tests conducted in VTT’s icing wind

tunnel, which fulfils the standard icing

conditions

• Time calculated from icing conditions start

to detector alarm

• Simultaneously the ice build-up on blades

was calculated

Test Conditions

• Temperature = -5 °C

• Droplet size = 17 µm

• Wind speed = 10 m/s

Calculation Methods

• Ice accretion calculations on wind turbine

blades were conducted with TURBICE

software

• Ice mass and thickness on blades were

calculated and measured when LID-

3300IP ice detector gave an alarm

Simulated Wind Turbine

• Typical multi-megawatt turbine

• Blade length 44 m

Test Results • LID-3300IP gave an ice alarm in average in 45

min after icy conditions started

• Ice mass on blades at alarm point 18 kg

• Ice thickness at alarm point

– Up to 1,3 cm at 85% radius

– Average ice thickness 1 cm

– Ice formed only on leading edge

• No large variations between the tests

Conclusions

• There is reliable link between LID-

3300IP alarm and ice build-up on

wind turbine blades

• It’s feasible to create common

standard and certification rules for

ice detection

Recommendations

• The ice detection standards should be created

• Common agreement on “standard” icy

conditions and best practices

• Helps wind turbine industry in ice detector

selection without time consuming and weather

dependent tests

Contact Information

• Technical questions Mr Jarkko Latonen

Tel.: +358 40 56 01 558,

E-mail: jarkko.latonen@labkotec.fi

• Commercial questions Mr Ole Martola

Tel.: +358 50 56 75 919,

E-mail: ole.martola@labkotec.fi